Through the siphons, it feeds on organic matter on the sediment surface or in the water.

Micraster was an infaunal echinoid living in a burrow below the sediment surface.

The exhalant siphon is kept below the sediment surface (about 1 cm).

Feeding activities of invertebrates on the sediment surface and plant matter promotes nutrient cycling.

They fed above the sediment surface, but were forced to burrow to avoid predators.

It includes the sediment surface and some sub-surface layers.

They can be preserved as widely scattered impressions or in close proximity to one another on the sediment surface.

Downcurrent these streaks start to gradually lift off from the sediment surface until they eventually "burst".

Many of the Diplichnites fossils are believed to be traces made by trilobites walking on the sediment surface.

Above this zone methane is only present in its dissolved form at concentrations that decrease towards the sediment surface.